System and Method for Automated Truck Loading

ABSTRACT

An automatic case loader for loading product in a trailer is disclosed. A mobile base structure provides a support framework for a drive subassembly, conveyance subassembly, an industrial robot, a distance measurement sensor, and a control subassembly. Under the operation of the control subassembly, product advances through a powered transportation path to an industrial robot which places the product within the trailer. The control subassembly coordinates the selective articulated movement of the industrial robot and the activation of the drive subassembly based upon the distance measurement sensor detecting objects within a detection space, dimensions of the trailer provided to the control subassembly, and dimensions of the product provided to the control subassembly.

PRIORITY STATEMENT & CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from co-pending U.S. Patent ApplicationNo. 60/939,689, entitled “System and Method for Automated Truck Loading”and filed on May 23, 2007, in the name of Tim Criswell; which is herebyincorporated by reference for all purposes.

TECHNICAL FIELD OF THE INVENTION

This invention relates, in general, to a machine for handling productsand, more particularly, to a system and method for automated truckloading which employ an automatic case loader designed to stack product,such as standard cardboard cases of various heights and widths, within atrailer.

BACKGROUND OF THE INVENTION

Loading docks and loading bays are commonly found in large commercialand industrial buildings and provide arrival and departure points forlarge shipments brought to or taken away by trucks and vans. By way ofexample, a truck may back into a loading bay such that the bumpers ofthe loading bay contact the bumpers on the trailer and a gap is createdbetween the loading bay and the truck. A dock leveler or dock platebridges the gap between the truck and a warehouse to provide a fixed andsubstantially level surface. Power moving equipment, such as forkliftsor conveyor belts, is then utilized to transport the cargo from thewarehouse to the truck. Human labor is then employed to stack the cargoin the truck. These systems are designed to maximize the amount thecargo loaded while minimizing the use of human labor to both protect andextend the life of the workforce. A need still exists, however, forimproved truck loading systems that further reduce the use of humanlabor.

SUMMARY OF THE INVENTION

An automatic case loader for loading product in a trailer is disclosed.A mobile base structure provides a support framework for a drivesubassembly, conveyance subassembly, an industrial robot, a distancemeasurement sensor, and a control subassembly. Under the operation ofthe control subassembly, product advances through a poweredtransportation path to an industrial robot which places the productwithin the trailer. The control subassembly coordinates the selectivearticulated movement of the industrial robot and the activation of thedrive subassembly based upon the distance measurement sensor detectingobjects within a detection space, dimensions of the trailer provided tothe control subassembly, and dimensions of the product provided to thecontrol subassembly. These systems and methodologies utilizing thepresent automatic case loader therefore maximize the amount the productand cargo loaded while minimizing the use of human labor to both protectand extend the life of the workforce.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is a side elevational view with partial cross-section of oneembodiment of an automatic case loader positioning product depicted ascases of various heights and widths within a trailer;

FIG. 2A is a side elevational view of the automatic case loaderillustrated in FIG. 1;

FIG. 2B is a front elevation view of the automatic case loaderillustrated in FIG. 1;

FIG. 2C is a front perspective view of the automatic case loaderillustrated in FIG. 1;

FIG. 3A is a perspective view of a portion of the automatic case loaderof FIG. 1 and in particular a detailed view of one embodiment of amobile base;

FIG. 3B is a side elevation view of the mobile base illustrated in FIG.3A;

FIG. 3C is a perspective view of an undercarriage of the mobile baseillustrated in FIG. 3A;

FIG. 4A and FIG. 4B are perspective views of one embodiment of a portionof a retractable wheel assembly which forms a portion of a drivesubassembly;

FIG. 5 is a perspective view of one embodiment of another portion of aretractable wheel assembly which forms a portion of a drive subassembly;

FIG. 6 is a perspective view of one embodiment of a universal wheelassembly which forms a portion of a drive subassembly;

FIGS. 7A through 7H are schematic diagrams of one operational embodimentof the automatic case loader of FIG. 1 stacking standard productdepicted as cases of various heights and widths in a trailer of a truck;

FIG. 8 is a schematic diagram of one embodiment of the automatic caseloader;

FIG. 9 is a schematic diagram of one embodiment of a robot controllerwhich forms a portion of the automatic case loader; and

FIG. 10 is a schematic diagram of one embodiment of a distancemeasurement sensor which forms a component of the automatic case loader.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of the presentinvention.

Referring initially to FIG. 1, therein is depicted an automatic caseloader that is schematically illustrated and generally designated 10.This automatic case loader 10 is utilized in systems and methods forautomated truck loading. A tractor trailer 12 having an operator cab 14is towing a trailer 16 having a front wall 18, two side walls 20A, 20B(best seen in FIGS. 7A through 7H), a floor 22, a ceiling 24, and a rearaccess opening 26 accessible due to an open door. A bumper 28 of thetrailer 16 is backed up to a loading bay 30 of loading dock 32 such thatthe bumper 28 touches a bumper 34 of the loading bay 30. A dock plate 36bridges the gap between the floor 22 and a deck 38 of the loading dock32.

As will be described in further detail hereinbelow, under thesupervision of distance measurement sensors that are components of theautomatic case loader 10, the automatic case loader 10 maneuvers anddrives automatically into the trailer 16 to a position proximate to thefront wall 18. It should be appreciated that although an operator 40 isdepicted as operating the automatic case loader 10, an operator isunnecessary. The automatic case loader 10 operates independently of theoperator 40 and the operator 40 is only necessary for certain types oftroubleshooting, maintenance, and the like. A telescoping conveyor unit42 having a skate wheel 44 for support and balance is connected to theautomatic case loader 10. A stream of product 46, in the form standardcardboard cases 46A-46H of various heights and widths, is being suppliedby the telescoping conveyor 42 which, in turn, loads the product 46 intothe trailer 16. In particular, the automatic case loader 10 has alreadystacked cases 46F, 46G, 46H at the intersection of the front wall 18 andthe floor 22. The automatic case loader 10 alternates between loadingthe product 46 and reversing to create more space for the product 46between the front wall 18 and the automatic case loader 10 until thetrailer 16 is at least partially loaded of product 46.

FIG. 2A through FIG. 2C depict the automatic case loader 10 in furtherdetail. A mobile base 50 supports a drive subassembly 52, a conveyancesubassembly 54, an industrial robot 56, a positioning subassembly 58, asafety subsystem 60, and a control subassembly 62, which interconnectsthe drive subassembly 52, conveyance subassembly 54, industrial robot56, positioning subassembly 58, and safety subsystem 60. The mobile base50 includes a front end 64 and a rear end 66 as well as sides 68, 70, asurface 72, and an undercarriage 74. An operator platform 76 ispositioned proximate to the rear end 66 and the side 68 to be adapted tosafely accommodate the operator 40.

The drive subassembly 52 is coupled to the undercarriage 74 of themobile base 50 to provide mobility. As will be discussed in furtherdetail hereinbelow, drive wheel assemblies 78, 80, are disposed on theundercarriage 74 proximate to the sides 70, 68 respectively. A universalwheel assembly 82 is disposed on the undercarriage 74 more proximate tothe rear end 66 and centered between the sides 68, 70, respectively. Incombination, wheel assemblies 78, 80, 82 provide forward and reversedrive and steering. Retractable wheel assemblies 84, 86 are alsodisposed on the undercarriage 74 proximate to the sides 70, 68,respectively. The retractable wheel assemblies 84, 86 have anorientation which is orthogonal to the retractable wheel assemblies 78,80 to, in conjunction with the universal wheel assembly 82, providetransverse drive and steering. As alluded to, in a forward or reversedrive and steering operation, such as moving into or out of the trailer16, drive wheel assemblies 78, 80 and the universal wheel assembly 82are actuated and in contact with the deck 38 of the loading dock 32while the retractable wheel assemblies 84, 86 are withdrawn from contactwith the deck 38 in a position close to the undercarriage 74. On theother hand, in a transverse drive and steering operation, such as arepositioning between loading bays at the loading dock 32, theretractable wheel assemblies 84, 86 and the universal wheel assembly 82are actuated and in contact with the deck 38 while the retractable wheelassemblies 78, 80 are off the deck 38. In particular, during traversemovement operations, the retractable wheel assemblies 78, 80hydraulically extend and lift the drive wheel assemblies 78, 80 off ofthe deck 38.

The conveyance subassembly 54 is disposed on the surface 72 of themobile base 50 to provide a powered transportation path 88 operable formeasuring, separating, carrying, and stacking, as required by theapplication and job assignment of the automatic case loader 10, productfrom the rear end 66 to the front end 64 proximate to the industrialrobot 56. As shown, the powered transportation path 88 includes apowered roller conveyor 90 having roller elements 92 which deliver theproduct 46 to a landing platform 94 where manipulation by the industrialrobot 56 is initiated. It should be appreciated that although only asingle powered roller conveyor 90 is display, the powered transportationpath 88 may include any combination and type of conveyors, elevators,stackers, and bypasses and the particular combination of componentsselected for the powered transportation path 84 will depend upon theparticular product 46 and application of the automatic case loader 10.

With respect to measuring the product 46, a curtain 96 may form aportion of the conveyance subassembly 54 and be disposed thereon tomeasure with light the dimensions of the product 46 and forward themeasured dimensions to the control subassembly 62 as will be discussedin more detail hereinbelow. It should be appreciated that the automaticcase loader 10 may be equipped with further product size detectionequipment in addition to the measuring light curtain 96. By way ofexample, spaced photo-eyes 98 disposed along the conveyance subassembly54 may measure the product length and determine if any product hasnon-standard or unacceptable length. As with the dimension data gatheredby the curtain 96, the product length data captured by the spacedphoto-eyes 98 is supplied to the control subassembly 62.

The conveyance subassembly 54 as well as the telescoping conveyor unit42 may also each be equipped with a series of end stop photo eyes, suchas end stop photo eyes 100, 102, to adjust the rate of automatic flow ofproduct through the telescoping conveyor unit 42 and the conveyancesubassembly 54. Such an implementation provides a steady and continuousflow of product, maintains proper product separation, and preventsunnecessary gaps between the product and product backups and jams.

A telescoping conveyor interface 104 couples the roller conveyor 90 ofthe conveyance subassembly 54 to the telescoping conveyor unit 42 andthe rest of a pick belt system which may be at the warehouse associatedwith the loading dock 32. Auto-follow circuitry associated with thetelescoping interface 104 of the telescoping conveyor unit 42 and theconveyance subassembly 54 may utilize fiber optic sensors at the lastboom of the telescoping conveyor unit detect reflective tape at the edgeof the conveyance subassembly to cause the telescoping conveyor unit 42to extend and retract to maintain the proper position with respect tothe automatic case loader 10.

The industrial robot 56 is disposed at the front end 64 and adapted toprovide selective articulated movement of an end effector 130 betweenthe landing platform 94 of the powered transportation path 88 and areachable space 132 such that the industrial robot 56 is operable toplace the product 46 in the reachable space 132. The end effector 130includes a gripper arm 134 adapted for manipulating product withopposing grapplers 136A, 136B. It should be appreciated that any type ofend effector 130 may be employed the industrial robot and the choice ofend effector 130 will depend upon the product 46 and specific automaticcase loader 10 application. By way of example, the gripper arm 134 withopposing grapplers 136A, 138B is preferred for loading rectangular cases46A-46H such as cardboard box cases of goods. It should be understood,however, that the product 46 may be any type of good such as tires orother non-cased objects requiring loading.

In one implementation, the industrial robot 56 includes seven segments130, 138, 140, 142, 144, 146, 148 joined by six joints 150, 152, 154,156, 158, 160 to furnish selective articulated movement having sixdegrees of freedom. More particularly, the referenced reachable space132, as best seen in FIG. 2C, is defined by the movement of theindustrial robot 56 which provides rotation about six axes includingrotary movement of the entire industrial robot 56 about a primaryvertical axis; rotary movement of segment 146 having a tower structureabout horizontal axis to provide extension and retraction of the segment144 having a boom arm; rotary movement of the boom arm about thehorizontal axis to provide raising and lowering of the boom arm; andselective rotary movement about three wrist axes.

The positioning subassembly 58 is dispersed throughout the mobile base50. A distance measurement sensor 170 disposed at the front end 64 ofthe mobile base 50 measures distance and determines the presence ofobjects within a detection space 172 which is located in front of thefront end 64. In one embodiment, the detection space 172 and thereachable space 132 at least partially overlap. The distance measurementsensor 170 assists the automatic case loader 10 with forward and reversemovement and the repositioning of the automatic case loader 10 to createadditional empty reachable space 132 for the placement of the product46. Further, the distance measurement sensor 170 assists with thecoordination and operation of the industrial robot 56. Distance andmeasurement information gathered by the distance measurement sensor 170is provided to the control subassembly 62.

As will be discussed in further detail hereinbelow, the distancemeasurement sensor 170 may be a laser range finding apparatus operatingon a time-of-flight measurement basis or principle. It should beappreciated, however, that other types of distance measurements arewithin the teachings of the present invention. By way of example, andnot by way of limitation, the distance measurement sensor may include alaser range finding apparatuses, ultrasonic measurement apparatuses,inclinometers, and combinations thereof. Similar to distance measurementsensor 170, distance measurement sensors 174, 176 are respectivelydisposed at the sides 68, 70. The distance measurement sensors 174, 176each include detection spaces (not illustrated) to provide measurementand distance information to the control subassembly 62 during traversemovement operations of the automatic case loader 10.

The safety subsystem 60 is distributed and mounted to the mobile base50. The safety subsystem 60 may include a light tower 180 which providesa quick indication of the current status of the automatic case loader 10to an operator 40 and a wireless operator alert system 182 whichcontacts pagers or cellular devices of individuals through a wirelessnetwork. Also a cage and railing 184 may be included around the operatorplatform 76 to provide additional safety to the operator 40. Emergencybuttons, such as emergency button 186, may be located throughout theautomatic case loader 10 to provide for instant and immediate powerdown. Front safety bumpers 188 and rear safety bumpers 190 may bepositioned at the front end 64 and the rear end 64 to protect theautomatic case loader 10, people, and product during a collision with anobstacle. Additionally, the front safety bumpers 188 and the rear safetybumpers 190 may include detectors that detect the presence of an objectand cause an automatic power down during a collision. Side safetybumpers, although not illustrated, may also be utilized. It should beappreciated that other safety features may be integrated into theautomatic case loader 10.

The control subassembly 62, which is also distributed and mounted to themobile base 50, includes control station 192 having a user interface 194disposed at the side 70 near the operator platform 76. As discussed, thedrive subassembly 52, the conveyance subassembly 54, the industrialrobot 56, the positioning subassembly 58, and the safety subassembly 60are interconnected and in communication with the control subassembly 62via a network of concealed and sheathed cables and wires. With thisarrangement, the control subassembly 62 may coordinate the manual andautomatic operation of the automatic case loader 10.

FIG. 3A through FIG. 3C depict the mobile base 50 in further detail. Amain frame 200 is constructed of welded steel tubing includes tubularsections 202, 204, 206, and 208 which provide a rectangular framework.The tubular sections 202-208 are supported by tubular sections 208, 210,214, 216, 218, and 220, which augment and further support therectangular framework. All mounting plates, such as mounting plates 222,224, 226, 228, 230, 232, 234, and bolt holes necessary to hold thevarious components attached to the mobile base 50 are included in themain frame 200. The large plates 228, 230, 232, 234 disposed toward therear end 66 of the mobile base 50 hold the control station 192 and theuser interface 194 in position while providing counter weight for theautomatic case loader 10 as well as balance with respect to theindustrial robot 56 disposed proximate to the mounting plates 222, 224.Additional counter weight is supplied by tractor weights 236, 238mounted proximate to the rear end 66, which also serve to add additionalsupport and integrity to the main frame 200. A tray 240 securely coupledto the main frame 200 by mounting brackets 242, 244 at the rear end 66provides support to the rear safety bumpers 190.

Drive wheel assemblies 78, 80 include a pair of front drive wheels 252,250 disposed proximate to the front end 64 and, more particularly,proximate the intersection of tubular sections 208, 214 and tubularsections 204, 214, respectively. Respective AC motors 254, 256 withdouble reduction gearboxes 258, 260 supply power thereto. The AC motor254 with double reduction gearbox 258 is disposed adjacent to thetubular section 214 and the front drive wheel 250. Similarly, the ACmotor 256 with double reduction gearbox 260 is disposed adjacent to thetubular section 214 and the front drive wheel 252.

Referring now to FIGS. 3A through 3C and FIGS. 4A through 4B, theretractable wheel assembly 84 includes a side lift wheel 262 with adrive motor 264 coupled thereto and providing rotational torque througha pulley 266. The side lift wheel 262 and the drive motor 264 aresecured to a frame 268 which, in turn, is coupled to the tubular section208. A hydraulic cylinder 270, under the power of a hydraulic powercylinder 272, is coupled to a crossbar mount 274 disposed on the frame268. The hydraulic power cylinder 272 is mounted via mounting bracket276 to the tubular section 216. Referring now to FIGS. 3A through 3C andFIG. 5, the retractable wheel assembly 86 includes a side lift wheel 278secured via a frame 280 to the tubular section 204. A crossbar mount 282secures the hydraulic cylinder 270 thereto such that the hydrauliccylinder 270 spans the space between the retractable wheel assemblies84, 86.

Referring now to FIGS. 3A through 3C and FIG. 6, the universal wheelassembly 82 includes a rear steering wheel 284 mounted to a frame 286disposed proximate to the rear end 66. An AC motor 288 with a reductiongearbox 290 provides power and is also coupled to the frame 286. Alsocoupled to the frame 286, a rotational mounting 292 is cooperating witha vertical axis 294 to furnish steering capability. A servomotor 296attached to a planetary gearbox 298 provides the steering motion.

Returning to FIGS. 3A through 6 to describe the operation of the drivesubassembly 52 in conjunction with the mobile base 50, the drive wheelassemblies 78, 80 and universal wheel assembly 82 provide mobility alongthe length of the automatic case loader 10. The AC motors 254, 256 withthe respective double reduction gearboxes 258, 260 drive the front drivewheels 250, 252. In particular, each front drive wheel 250, 252 isindependently driven to provide the ability to turn and to provide apivoting drive mode. The universal wheel assembly 82 provides a rearcombination steering and drive wheel 284 that is driven by the AC motor288 and the gearbox 290. The rear steering wheel 284 spins on thevertical axis 294 to provide enhanced steering capability for theautomatic case loader 10.

In addition to providing forward and reverse capability, the drivesubassembly 52 furnishes a traverse drive system providing thecapability to move the entire automatic case loader 10 perpendicular toa trailer or fixed object at the loading dock 32. During normaloperation, the retractable wheel assemblies 84, 86 and particularly theside lift wheels 262, 270 are tucked up under the main frame 200. Whentraverse mode is activated, the hydraulic cylinder 270 forces the sidelift wheels 262, 270 down, lifting the front drive wheels 250, 252 offof the ground. The drive motor 264 provides rotational torque to theside lift wheel 262 while the side lift wheel 278 is passive and followsthe side lift wheel 262. In this embodiment, the steering and drivewheel 284 of the universal wheel assembly 82 rotates and providessteering.

Referring now to FIGS. 7A through 7H, wherein one embodiment of anautomated loading system and methodology are illustrated for theautomatic case loader 10 of the present invention. Initially, as shownin FIG. 7A, the trailer 16 is positioned under the power of the tractortrailer 12 at the loading bay 30 of the loading dock 32 approximate tothe deck 38 where the automatic case loader 10 is working. The trailer16 is set-up, cleaned, and activated in a usual manner. The dock plate36 is deployed from the loading bay 30 into the trailer 16 to provide abridge. Thereafter, the trailer 16 is inspected for significant damagethat may interfere with the automated loading operations of theautomatic case loader 10. Additional inspection may include ensuring thetrailer is reasonably centered within the loading bay 30 and ensuringthe deck 38 is clear of any obstructions. At this time, by way offurther safety measures, a kingpin lockout may be installed to prevent adriver from accidentally pulling out the trailer 16 from the loading bay30 when the automatic case loader 10 is operating within the trailer 16.The kingpin lockout or similar safety precautions protect both theoperator 40 and the equipment and ensures that the wheels of the trailer16 are chocked and will not roll during the use of the automatic caseloader 10.

Continuing to refer to FIG. 7A, once the trailer 16 is positioned in theloading bay 30, the automatic case loader 10 is moved in front of therear access opening 26 of the trailer 16. The automatic case loader 10utilizes either a manual or automatic reverse mode to assist theoperator 40 in backing the automatic case loader 10 up to thetelescoping conveyer unit 42 in a position that is square thereto. Theconveyance subassembly 54 of the automatic case loader 10 is thencoupled to the telescoping conveyor unit 42. At this time, as the dockplate 36 has been positioned from the deck 38 to the trailer 16, theautomatic case loader 10 may be advanced into the interior of thetrailer 16.

With reference to FIG. 7B, the automatic case loader 10 has advancedforward into the trailer 16 and, in one embodiment, the positioningsubassembly 58 and, in particular, the distance measurement sensor 170continuously determines the position of the automatic case loader 10within the trailer 16. More specifically, several measurements are made.The position and angle of the automatic case loader 10 are measured withrespect to the sidewalls 20A, 20B and an interior width defined thereby.Also, measurements are made with respect to a near wall within thetrailer 16 and the floor 22. The near wall being the closer of the frontwall 18 of the trailer or the edge formed by product 46, e.g. cases,positioned within the trailer 16. The angle relative to the floor 22proximate to the automatic case loader 10 is measured as the automaticcase loader traverses the dock plate 36 and moves into the trailer 16.In one embodiment, following successful traversal, the angle relative tothe floor 22 may be assumed to be constant.

In this way, as the automatic case loader 10 moves, the position of theautomatic case loader 10 relative to objects in its environment is knownand the automatic case loader 10 may adjust operation appropriately.Adjustments in operation may include, but are not limited to, theoperation of the industrial robot 56, the operation of the conveyancesubassembly 54, and the actuation of the drive subassembly 52. Theposition of the sidewalls 20A, 20B and the near wall is utilized todetermine the position of the automatic case loader 10 along the lengthof the trailer 16, the position across the width of the trailer 16, andthe automatic case loader's angle relative to the sidewalls 20A, 20B oryaw. The measurements also determine the position of the automatic caseloader 10 relative to the floor 22 of the trailer 16. To assist theautomatic case loader 10 in determining position within the trailer 16,in one implementation, the automatic case loader 10 is programmed withthe dimensions of the trailer 16.

Additionally, in one embodiment, the automatic case loader 10 isprogrammed with the reachable space 132 of the industrial robot 56. Asillustrated, once the automatic case loader is positioned proximate tothe front wall 18 of the trailer 16 such that the placement of product46 against the front wall 18 of the trailer 16 is within the reachablespace 132 of the industrial robot 56, the automatic case loader 10 stopsadvancing. Referring now to FIG. 7C, product 46 is conveyed from thetelescoping conveyor unit 42 to the conveyance subassembly 54 and thisstream of product 46 is presented to the industrial robot 56. Withselective articulated movement through the reachable space 132, theindustrial robot 56 places the product 46 within the trailer andsequentially loads the product 46 according to a stacking routinedesigned to optimize the use of available space within the trailer 16.

In one embodiment, this stacking routine places product in sequentiallyvertically stacked horizontal rows. By way of example, FIG. 7Cillustrates a first stacked horizontal row being completed. Thisstacking routine or other alternative stacking routine may be optimizedfor the size of the end effector 130 of the industrial robot 56, thedimensions of the trailer 16, and the dimensions of the product 46.

As depicted in FIG. 7D, the automatic case loader 10 has completedstacking a second horizontal row of product 46 on top of the firsthorizontal row of product 46. The loading of the product 46 by theindustrial robot 56 is temporarily interrupted in response to thedistance measurement sensor 170 detecting the presence of the product 46within the reachable space 132. Further, with this information beingavailable to the control subassembly 62, a signal may be sent to theconveyance subassembly 54 to slow down or temporarily halt the poweredtransport of the product 46.

Referring now to FIG. 7E, the automatic case loader 10 has reversed andrepositioned to refresh the reachable space 132 such that the automaticcase loader 10 is positioned proximate to the wall of placed product 46in order that the placement of additional product 46 against the wall ofplaced product 46 is within the reachable space 132 of the industrialrobot 56. During the repositioning of the automatic case loader 10, thetelescoping conveyor unit 42 appropriately retracts, while maintainingcontact with the conveyance subassembly 54, to accommodate the newposition of the automatic case loader 10.

Referring to FIG. 7F, the iterative stacking operations andrepositioning of the automatic case loader 10 described in FIGS. 7Cthrough 7E continues and the trailer 16 is filled. With respect to FIG.7G, the trailer 16 is completely filled with product 46 and theautomatic case loader 10 is reversed to a position entirely on the deck38. Thereafter, as shown in FIG. 7H, the trailer 16 filled with product46 leaves the loading dock 32. A fresh empty trailer may then bepositioned at the loading bay 30 and loaded in the manner describedherein.

FIG. 8 depicts one embodiment of the automatic case loader 10 and thecontrol signals associated therewith. The illustrated componentscoordinate the various functions and operations of the automatic caseloader 10. The user interface 194, operational environment database 350,programmable logic controller 352, robot controller 354, and distancemeasurement sensors 170, 174, 176 are interconnected. The drivesubassembly 52, conveyance subassembly 54, as represented by control 356for conveyors/elevators, and safety controller 358 are connected to theprogrammable logic controller 352. Finally, the industrial robot 56 isconnected to the robot controller 354. In one implementation, the userinterface 194, operational environment database 350, and programmablelogic controller 352 are part of the control subassembly 62 and therobot controller 354 forms a portion of the industrial robot 56. Thesafety controller 358 is included in the safety subsystem 60 andprovides operation to the aforementioned components of this subsystem.

The user interface 194 provides user control and interaction with theautomatic case loader 10. The user interface 194 may utilize icons inconjunction with labels and/or text to provide navigation and a fullrepresentation of the information and actions available to the operator.In addition to loading operations, user interactions may be related tomaintenance, repair and other routine actions which keep the automaticcase loader 10 in working order or prevent trouble from arising.

The operational data environment database 350 includes data about thereachable space 132 of the industrial robot 56, stacking methodologydata, product information as well as information about the standardsizes of trailers. The product information may be stored in theoperational data environment database 350, gathered by the conveyancesubassembly 54 as previously discussed, or gained by a combinationthereof. By having the standard sizes of trailers pre-loaded, operatortime is saved from having to enter this data and performance of theautomatic case loader 10 is improved with this additional information.By way of example, Tables I & II present exemplary examples of type oftrailer data that the automatic case loader 10 may utilize indetermining position and product placement.

TABLE I TRAILER DIMENSIONS Inside Inside Door Trailer Inside HeightHeight Opening Type Length Width Center Front Width 28′ 27′3″ 100″ 109″107″ 93″ (8.5 m) (8.3 m) (2.5 m) (2.8 m) (2.7 m) (2.4 m) High Cube 45′44′1- 93″ 109″ 106″ 87″ (13.7 m) 1/2″ (2.4 m) (2.8 m) (2.7 m) (2 m)Wedge (13.4 m) 48′ 47′3″ 99″ 110-1/2″ 108-1/2″ 93″ (14.6 m) (14.4 m)(2.5 m) (2.8 m) (2.8 m) (2.4 m) Wedge

TABLE II TRAILER DIMENSIONS CONTINUED Door Rear Trailer Opening FloorCubic Overall Overall Type Height Height Capacity Width Height 28′ 104″47-1/2″ 2029 cft 102″ 13′6″ (8.5 m) (2.6 m) (1.2 m) (57.5 cm) (2.6 m)(4.1 m) High Cube 45″ 105-1/2″ 50″ 3083 cft 96″ 13′6″ (13.7 m) (2.7 m)(1.3 m) (7.3 cm) (2.4 m) (4.1 m) Wedge 48′ 105″ 48-1/2″ 3566 cft 102″13′6″ (14.6 m) (2.7 m) (1.2 m) (101 cm) (2.6 m) (4.1 m) Wedge

The programmable logic controller 352 coordinates overall operation andswitches between various modes of operation including manual andautomatic. The programmable logic controller 352 also provides for thehigh-level calculation and coordination required during automaticoperation for items such as the stack height during loading and steeringangel calculations during automatic navigation.

The robot controller 354 controls the motions of the industrial robot 56through built in inputs and outputs wired through the industrial robot56 and the end effector 130. It should be appreciated that although aparticular architecture is presented for the control of the automaticcase loader, other architectures are within the teachings of the presentinvention. By way of example, any combination of hardware, software, andfirmware may be employed. By way of further example, the distribution ofcontrol may differ from that presented herein.

In one operation embodiment, the programmable logic controller 352accesses the dimensions of the trailer 16 from the operationalenvironment database 352. The operator 40 has indicated through the userinterface 194 which type of trailer has arrived at the docking bay 30.Alternatively, the distance measurement sensor 170 is operable to detectthis information. The distance measurement sensors 170, 174, 176 relaydistance and position data to the programmable logic controller 352which uses this information to send control signals to the robotcontroller 354, the drive subassembly 52, the controller 352, and thesafety controller 358. Additionally, the programmable logic controller352 receives control signals, which are inputs into the behaviorprocess, from each of these components. Constant updates and statusinformation are provided to the operator 40 by the programmable logiccontroller 352 through the user interface 194.

FIG. 9 depicts one embodiment of the robot controller 354 which forms aportion of the automatic case loader 10. The essence of the robotcontrol 352 is a robot system or control program 360, which controls theindustrial robot 56. The control program 360 can be operated by theoperator 40 by means of an operating service 362 in communication withthe user interface 194 and receives input data (as well as provideinstructions, as appropriate) from the operational environmentaldatabase 350, programmable logic controller 352, and distancemeasurement sensor 170 by means of a driver 364. It should beappreciated, that the independence of the robot controller 354 may vary.In one implementation, the robot controller 354 may be under the controlof the programmable logic controller 352. In another implementation, asillustrated, the robot controller 354 is more autonomous and may includefeatures such as direct connection to the user interface 194.

According to one embodiment, between the driver 364 and the controlprogram 360 is provided an independent data processing layer in the formof a frame program 366, which controls the robot movements, and a unit368 for automated or event-controlled strategy or behavioral selectionon the basis of the states and signals which occur. User applicationprograms, event-controlled strategy selections and sensor programs inthe frame program 366 can be programmed by the operator 40 and directedby a robot program 370, which monitors the balance and implementation ofmanual and automatic control of the industrial robot 56.

FIG. 10 depicts one embodiment of a distance measurement sensor, i.e., alaser measurement sensor 380. A staging circuit 382 causes a pulsedlaser 384 to transmit light pulses while causing the rotation of a lightdeflecting device 386 via controller 388 which may be equipped with arotational means and a motor. The angular position of the lightdeflecting device 386 is continuously communicated to the stagingcircuit 382 by the controller 388. Light pulses are transmitted into thedetection space 172 via the transmitter lense and the mirrors associatedwith the light deflection device 386. More particularly, when the rotarymirror of the light deflection device 386 is driven by the controller388 to execute a continuous rotary movement, the staging circuit 382causes the pulsed laser 384 to transmit a light pulse. The light pulseis transmitted into the detection space 172 and is reflected from anobject, so that finely a received pulse enters into a photo receivingarrangement 390. In this manner the light reaches the photo receiverarrangement 390 after a light transit time t of 2d/c, where d is thespace in the object from the apparatus and c is the speed of light.

The time t between the transmission and reception of the light pulse ismeasured with the aid of a comparator 392 having time interval computerfunctionality. On transmitting the light pulse, a counter functionwithin the comparator 392 is triggered and is stopped again by the photoreceiver arrangement 390 via the comparator 392 on receiving the lightpulse from the detection space 172.

A corresponding electrical signal is formed and applied via comparator392 to a laser scanner controller 394, signal to noise processor 396 anda detector 398, which analyzes the signal for objects and in the instantexample determines that an object is present. The task of the signal tonoise processor 396 is to control the detection threshold independenceon the received noise level. This control ensures a constant false alarmrate with varying illumination situations and object reflection factors.The signal to noise processor 396 makes available this information tothe laser scanner controller 394. The laser scanner controller 394performs peak value calculations based on the data from the comparator392, the signal to noise processor 396, and the detector 398.

As the laser scanner controller 394 knows the instantaneous angularposition of the light pulses by way of communication with the stagingcircuit 382, the laser scanner controller 394 determines the location ofthe object and other navigational properties. The laser scannercontroller 394 is adapted to forward this information to othercomponents.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

1. An automatic case loader for loading product in a trailer, theautomatic case loader comprising: a mobile base structure having firstand second ends; a drive subassembly coupled to the mobile base, thedrive subassembly including a plurality of wheels for steering anddriving the mobile base; a conveyance subassembly disposed on the mobilebase, the conveyance subassembly including a powered transportation pathoperable for transporting product from the first end to the second end;an industrial robot disposed at the second end of the mobile base, theindustrial robot providing selective articulated movement of an endeffector between the powered transportation path and a reachable spacesuch that the industrial robot is operable to place the product in thereachable space; a distance measurement sensor disposed at the secondend, the distance measurement sensor for determining presence of objectswithin a detection space, wherein the detection space and the reachablespace at least partially overlap; and a control subassembly mounted tothe mobile base structure, the control subassembly being incommunication with the drive subassembly, the industrial robot, and thedistance measurement sensor, the control subassembly coordinating theselective articulated movement of the industrial robot and theactivation of the drive subassembly based upon the distance measurementsensor detecting objects within the detection space, dimensions of thetrailer provided to the control subassembly, and dimensions of theproduct provided to the control subassembly.
 2. The automatic caseloader as recited in claim 1, wherein the plurality of wheels furthercomprises a pair of front drive wheels disposed proximate to the secondend, the pair of front drive wheels being powered by respective ACmotors with double reduction gearboxes.
 3. The automatic case loader asrecited in claim 1, wherein the plurality of wheels further comprises arear drive wheel disposed proximate to the first end, the rear drivewheel being powered by an AC motor with a reduction gearbox and mountedto a vertical axis to provide steering capability.
 4. The automatic caseloader as recited in claim 1, wherein the conveyance subassembly furthercomprises a conveyor having a telescoping conveyor interface forcoupling the automatic case loader to a telescoping conveyor unit. 5.The automatic case loader as recited in claim 1, wherein the conveyancesubassembly further comprises a powered roller conveyor.
 6. Theautomatic case loader as recited in claim 1, wherein the industrialrobot comprises seven segments joined by six joints to furnish selectivearticulated movement having six degrees of freedom.
 7. The automaticcase loader as recited in claim 1, wherein the end effector comprises agripper arm adapted for manipulating product with opposing grapplers. 8.The automatic case loader as recited in claim 1, wherein the distancemeasurement sensor comprises a laser range finding apparatus operatingon a time-of-flight measurement principle.
 9. The automatic case loaderas recited in claim 1, wherein the distance measurement sensor comprisesa device selected from the group consisting of laser range findingapparatuses, ultrasonic measurement apparatuses, inclinometers, andcombinations thereof.
 10. The automatic case loader as recited in claim1, wherein the dimensions of the trailer are programmed into the controlsubassembly.
 11. The automatic case loader as recited in claim 1,wherein the dimensions of the product are programmed into the controlsubassembly.
 12. The automatic case loader as recited in claim 1,wherein the conveyance subassembly further comprises a curtain formeasuring with light the dimensions of the product and forwarding themeasured dimensions to the control subassembly.
 13. An automatic caseloader for loading product in a trailer, the automatic case loadercomprising: a mobile base structure having first and second ends; adrive subassembly coupled to the mobile base, the drive subassemblyincluding a plurality of wheels for steering and driving the mobilebase; means for conveying product from the first end to the second endof the mobile base; an industrial robot disposed at the second end ofthe mobile base, the industrial robot providing selective articulatedmovement of an end effector through a reachable space such that theindustrial robot is operable manipulate the product within the reachablespace; means for determining presence of objects within a detectionspace proximate to the second end of the mobile base, the detectionspace and the reachable space at least partially overlap; and a controlsubassembly mounted to the mobile base structure, the controlsubassembly being in communication with the drive subassembly, theindustrial robot, and the means for determining presence, the controlsubassembly coordinating the selective articulated movement of theindustrial robot and the activation of the drive subassembly based uponthe means for determining presence detecting objects within thedetection space, dimensions of the trailer provided to the controlsubassembly, and dimensions of the product provided to the controlsubassembly.
 14. The automatic case loader as recited in claim 13,wherein the dimensions of the trailer are programmed into the controlsubassembly.
 15. The automatic case loader as recited in claim 1,wherein the dimensions of the product are programmed into the controlsubassembly.
 16. The automatic case loader as recited in claim 1,wherein the means for conveying product further comprises a curtain formeasuring with light the dimensions of the product and forwarding themeasured dimensions to the control subassembly.
 17. A method forstacking product within a trailer parked at a loading bay, the methodcomprising: positioning an automatic case loader including a mobile basestructure having first and second ends under the power of a drivesubassembly proximate to the loading bay; connecting a conveyancesubassembly disposed on the mobile base to a telescoping conveyor unithaving a supply of product associated therewith; driving the automaticcase loader into the trailer; detecting the location of the automaticcase loader within the trailer with a distance measurement sensordisposed on the mobile base structure; stopping, in response to distancemeasurement data from the distance measurement sensor, the automaticcase loader proximate to the front wall of the trailer; presenting astream of product to an industrial robot disposed on the mobile basestructure, the industrial robot providing selective articulated movementthrough a reachable space such that the industrial robot is operable toplace the product within the trailer; sequentially loading the productwithin the trailer with the industrial robot according to a stackingroutine designed to optimized the use of available space within thetrailer; interrupting the loading of product in response to detection bythe distance measurement sensor presence of product within the reachablespace; reversing and repositioning the automatic case loader to refreshthe reachable space; and resuming the sequential loading of the product.18. The method as recited in claim 17, wherein sequentially loading theproduct within the trailer further comprises utilizing a stackingroutine which places product in sequentially vertically stackedhorizontal rows.
 19. The method as recited in claim 17, whereinsequentially loading the product within the trailer further comprisesutilizing a stacking routine optimized for size of an end effector ofthe industrial robot, dimensions of the trailer, and dimensions of theproduct.
 20. A method for stacking product within a trailer parked at aloading bay, the method comprising: positioning an automatic case loaderincluding a mobile base structure having first and second ends under thepower of a drive subassembly proximate to the loading bay; connecting aconveyance subassembly disposed on the mobile base to a telescopingconveyor unit having a supply of product associated therewith; drivingthe automatic case loader into the trailer; measuring position and angleof the automatic case loader with respect to sidewalls and interiorwidth of the trailer with a distance measurement sensor disposed on themobile base structure; measuring position of the automatic case loaderwith respect to a near wall within the trailer with the distancemeasurement sensor, the near wall being the closer to the automatic caseloader of the front wall of the trailer and edge formed by productpositioned within the trailer; measuring position of the automatic caseloader with respect to a floor of the trailer with the distancemeasurement sensor; stopping, in response to distance measurement datafrom the distance measurement sensor, the automatic case loaderproximate to the front wall of the trailer; presenting a stream ofproduct to an industrial robot disposed on the mobile base structure,the industrial robot providing selective articulated movement through areachable space such that the industrial robot is operable to place theproduct within the trailer; sequentially loading the product within thetrailer with the industrial robot according to a stacking routinedesigned to optimized the use of available space within the trailer;interrupting the loading of product in response to detection by thedistance measurement sensor presence of product within the reachablespace; reversing and repositioning the automatic case loader to refreshthe reachable space; and resuming the sequential loading of the product.21. The method as recited in claim 20, wherein sequentially loading theproduct within the trailer further comprises utilizing, by theindustrial robot, the measurements of the distance measurement sensor toplace product.